TLR Signaling Pathway Gene Polymorphisms, Gene-Gene and Gene-Environment Interactions in Allergic Rhinitis.

Background: Allergic rhinitis (AR) is a nasal inflammatory disease resulting from a complex interplay between genetic and environmental factors. The association between Toll-like receptor (TLR) signaling pathway and environmental factors in AR pathogenesis remains to be explored. This study aims to assess the genetic association of AR with single nucleotide polymorphisms (SNPs) in TLR signaling pathway, and investigate the roles of gene-gene and gene-environment interactions in AR. Methods: A total of 452 AR patients and 495 healthy controls from eastern China were enrolled in this hospital-based case-control study. We evaluated putatively functional genetic polymorphisms in TLR2, TLR4 and CD14 genes for their association with susceptibility to AR and related clinical phenotypes. Interactions between environmental factors (such as traffic pollution, residence, pet keeping) and polymorphisms with AR were examined using logistic regression. Models were stratified by genotype and interaction terms, and tested for the significance of gene-gene and gene-environment interactions. Results: In the single-locus analysis, two SNPs in CD14, rs2563298 (A/C) and rs2569191 (C/T) were associated with a significantly decreased risk of AR. Compared with the GG genotype, the GT and GT/TT genotypes of TLR2 rs7656411 (G/T) were associated with a significantly increased risk of AR. Gene-gene interactions (eg, TLR2 rs7656411, TLR4 rs1927914, and CD14 rs2563298) was associated with AR. Gene-environment interactions (eg, TLR4 or CD14 polymorphisms and certain environmental exposures) were found in AR cases, but they were not significant after Bonferroni correction. Conclusion: The genetic polymorphisms of TLR2 and CD14 and gene-gene interactions in TLR signaling pathway were associated with susceptibility to AR in this Han Chinese population. However, the present results were limited to support the association between gene-environment interactions and AR.

Dose-effect relationships of 12C6+ ions-induced dicentric plus ring chromosomes, micronucleus and nucleoplasmic bridges in human lymphocytes in vitro.

PURPOSE: The objective of this research was to explore the dose-effect relationships of dicentric plus ring (dic + r), micronucleus (MN) and nucleoplasmic bridges (NPB) induced by carbon ions in human lymphocytes. MATERIALS AND METHODS: Venous blood samples were collected from three healthy donors. 12C6+ ions beam was used to irradiate the blood samples at the energy of 330 MeV and linear energy transfer (LET) of 50 keV/µm with a dose rate of 1 Gy/min in the spread-out Bragg peak. The irradiated doses were 0 (sham irradiation), 1, 2, 3, 4, 5 and 6 Gy. Dic + r chromosomes aberrations were scored in metaphases. The cytokinesis-block micronucleus cytome (CBMN) was conducted to analyze MN and NPB. The maximum low-dose relative biological effectiveness (RBEM) values of the induction of dic + r, MN and NPB in human lymphocytes for 12C6+ ions irradiation was calculated relative to 60Co γ-rays. RESULTS: The frequencies of dic + r, MN and NPB showed significantly increases in a dose-depended manner after exposure to 12C6+ ions. The distributions of dic + r and MN exhibited overdispersion, while the distribution of NPB agreed with Poisson distribution at all doses. Linear-quadratic equations were established based on the frequencies of dic + r and MN. The dose-response curves of NPB frequencies followed a linear model. The derived RBEM values for dic + r, MN and NPB in human lymphocytes irradiated with 12C6+ ions were 8.07 ± 2.73, 2.69 ± 0.20 and 4.00 ± 2.69 in comparison with 60Co γ-rays. CONCLUSION: The dose-response curves of carbon ions-induced dic + r, MN and NPB were constructed. These results could be helpful to improve radiation risk assessment and dose estimation after exposed to carbon ions irradiation.

Effect of nicotine on Staphylococcus aureus biofilm formation and virulence factors.

Staphylococcus aureus is a common pathogen in chronic rhinosinusitis (CRS) patients, the pathogenesis of which involves the ability to form biofilms and produce various virulence factors. Tobacco smoke, another risk factor of CRS, facilitates S. aureus biofilm formation; however, the mechanisms involved are unclear. Here, we studied the effect of nicotine on S. aureus biofilm formation and the expression of virulence-related genes. S. aureus strains isolated from CRS patients and a USA300 strain were treated with nicotine or were untreated (control). Nicotine-treated S. aureus strains showed dose-dependent increases in biofilm formation, lower virulence, enhanced initial attachment, increased extracellular DNA release, and a higher autolysis rate, involving dysregulation of the accessory gene regulator (Agr) quorum-sensing system. Consequently, the expression of autolysis-related genes lytN and atlA, and the percentage of dead cells in biofilms was increased. However, the expression of virulence-related genes, including hla, hlb, pvl, nuc, ssp, spa, sigB, coa, and crtN was downregulated and there was reduced bacterial invasion of A549 human alveolar epithelial cells. The results of this study indicate that nicotine treatment enhances S. aureus biofilm formation by promoting initial attachment and extracellular DNA release but inhibits the virulence of this bacterium.

Nicotine Enhances Staphylococcus epidermidis Biofilm Formation by Altering the Bacterial Autolysis, Extracellular DNA Releasing, and Polysaccharide Intercellular Adhesin Production.

Staphylococcus epidermidis is a common bacterial colonizer of human skin and mucous membranes, yet it has emerged as an important nosocomial pathogen largely due to its ability to form biofilms. Tobacco smoke has been demonstrated as a contributor to various infection diseases by improving the biofilm formation of multiple bacterial species; however, the association between tobacco smoke and S. epidermidis biofilm is still unclear. In this study, we tested the effect of nicotine, one of the most active components of tobacco, on S. epidermidis biofilm formation, and we studied the underlying mechanisms. Our results showed that nicotine promoted the biofilm formation of S. epidermidis 1457 strain (SE1457) and enhanced its initial attachment to a polyethylene surface as well as polysaccharide intercellular adhesin (PIA) production. In addition, an increased extracellular DNA release and a higher autolysis rate of SE1457 was detected after nicotine treatment, which was consistent with the increased ratio of dead cells in nicotine-treated SE1457 biofilm observed with confocal laser-scanning microscopy. Furthermore, the effect of nicotine on several autolysis-related and biofilm-related gene knockout mutants of SE1457 was tested. It showed that in ΔsaeRS, ΔlytSR, and ΔsceD, nicotine induced increase in biofilm formation was similar to that in SE1457; but in ΔarlRS, ΔatlE, and ΔicaC, the effect was obviously impaired. Consistently, the increase of the bacterial autolysis rate in ΔarlRS and ΔatlE induced by nicotine was not as significant as that in SE1457. Meanwhile, the growth inhibition of nicotine on SE1457 was observed, and it was much less on ΔarlRS and restored by the arlRS complementation. The arlRS transcription in SE1457 was inhibited by nicotine during cultivation as indicated by a promoter reporter assay using green fluoresent protein. Taken together, our study indicates that nicotine improves S. epidermidis biofilm formation by promoting its initial attachment and intercellular accumulation; the arlRS, atlE, and ica genes mediating bacterial autolysis and PIA production play an important role in this process.

GDF-15 gene expression alterations in human lymphoblastoid cells and peripheral blood lymphocytes following exposure to ionizing radiation.

The identification of rapid, sensitive and high­throughput biomarkers is imperative in order to identify individuals harmed by radiation accidents, and accurately evaluate the absorbed doses of radiation. DNA microarrays have previously been used to evaluate the alterations in growth/differentiation factor 15 (GDF15) gene expression in AHH­1 human lymphoblastoid cells, following exposure to γ­rays. The present study aimed to characterize the relationship between the dose of ionizing radiation and the produced effects in GDF­15 gene expression in AHH­1 cells and human peripheral blood lymphocytes (HPBLs). GDF­15 mRNA and protein expression levels following exposure to γ­rays and neutron radiation were assessed by reverse transcription­quantitative polymerase chain reaction and western blot analysis in AHH­1 cells. In addition, alterations in GDF­15 gene expression in HPBLs following ex vivo irradiation were evaluated. The present results demonstrated that GDF­15 mRNA and protein expression levels in AHH­1 cells were significantly upregulated following exposure to γ­ray doses ranging between 1 and 10 Gy, regardless of the dose rate. A total of 48 h following exposure to neutron radiation, a dose­response relationship was identified in AHH­1 cells at γ­ray doses between 0.4 and 1.6 Gy. GDF­15 mRNA levels in HPBLs were significantly upregulated following exposure to γ­ray doses between 1 and 8 Gy, within 4­48 h following irradiation. These results suggested that significant time­ and dose­dependent alterations in GDF­15 mRNA and protein expression occur in AHH­1 cells and HPBLs in the early phases following exposure to ionizing radiation. In conclusion, alterations in GDF­15 gene expression may have potential as a biomarker to evaluate radiation exposure.

5-aminolevulinic acid-mediated photodynamic therapy and its strain-dependent combined effect with antibiotics on Staphylococcus aureus biofilm.

Staphylococcus aureus (S. aureus) is hard to be eradicated, not only due to the emergence of antibiotic resistant strains but also because of its ability to form biofilm. Antibiotics are the major approach to treating biofilm infections, but their effects are unsatisfactory. One of the potential alternative treatments for controlling biofilm infections is photodynamic therapy (PDT), which requires the administration of photosensitizer, followed by light activation. 5-aminolevulinic acid (ALA), a natural photosensitizer prodrug, presents favorable characteristics, such as easy penetration and rapid clearance. These advantages enable ALA-based PDT (ALA-PDT) to be well-tolerated by patients and it can be repeatedly applied without cumulative toxicity or serious side effects. ALA-PDT has been proven to be an effective treatment for multidrug resistant pathogens; however, the study of its effect on S. aureus biofilm is limited. Here, we established our PDT system based on the utilization of ALA and a light-emitting diode, and we tested the effect of ALA-PDT on S. aureus biofilm as well as the combined effect of ALA-PDT and antibiotics on S. aureus biofilm. Our results showed that ALA-PDT has a strong antibacterial effect on S. aureus biofilm, which was confirmed by the confocal laser scanning microscope. We also found that lethal photosensitization occurred predominantly in the upper layer of the biofilm, while the residual live bacteria were located in the lower layer of the biofilm. In addition, the improved bactericidal effect was observed in the combined treatment group but in a strain-dependent manner. Our results suggest that ALA-PDT is a potential alternative approach for future clinical use to treat S. aureus biofilm-associated infections, and some patients may benefit from the combined treatment of ALA-PDT and antibiotics, but drug sensitivity testing should be performed in advance.

Necessity of Internal Monitoring for Nuclear Medicine Staff in a Large Specialized Chinese Hospital.

This work intends to quantify the risk of internal contaminations in the nuclear medicine staff of one hospital in Henan province, China. For this purpose, the criteria proposed by the International Atomic Energy Agency (IAEA) to determine whether it is necessary to conduct internal individual monitoring was applied to all of the 18 nuclear medicine staff members who handled radionuclides. The activity of different radionuclides used during a whole calendar year and the protection measures adopted were collected for each staff member, and the decision as to whether nuclear medicine staff in the hospital should be subjected to internal monitoring was made on the basis of the criteria proposed by IAEA. It is concluded that for all 18 members of the nuclear medicine staff in the hospital, internal monitoring is required. Internal exposure received by nuclear medicine staff should not be ignored, and it is necessary to implement internal monitoring for nuclear medicine staff routinely.

Dose-effect of ionizing radiation-induced PIG3 gene expression alteration in human lymphoblastoid AHH-1 cells and human peripheral blood lymphocytes.

PURPOSE: To identify new ionizing radiation (IR)-sensitive genes and observe the dose-effect of gene expression alteration (GEA) induced by IR. MATERIALS AND METHODS: Microarray was used to screen the differentially expressed genes in human lymphoblastoid cells (AHH-1) using three doses of (60)Co γ-rays (0.5-8 Gy at 1 Gy/min). Given that p53-inducible gene 3 (PIG3) was consistently upregulated, the GEA of PIG3 in AHH-1 cells and human peripheral blood lymphocytes (HPBL) induced by γ-rays (1 Gy/min) was measured at messenger RNA (mRNA) and protein levels. The GEA of PIG3 in AHH-1 cells exposed to neutron radiation (californium-252, 0.073 Gy/min) was also quantified. RESULTS: PIG3 was one of the seven differentially expressed genes found in the microarray analysis. The PIG3 mRNA and protein levels in AHH-1 cells were significantly increased from 1-10 Gy of γ-rays 8-72 h or 8-168 h after exposure, respectively. The enhancement was also observed in AHH-1 cells from 0.4-1.6 Gy of neutrons 48 h post-irradiation. The PIG3 mRNA levels (mRNA copy numbers) in HPBL were significantly increased from 1-8 Gy of γ-rays within 4-24 h post-irradiation, but the highest increase in signal-to-noise responsiveness is approximately two-fold, which was less than that of AHH-1 (approximately 20-fold). CONCLUSIONS: IR can upregulate the PIG3 gene expression in AHH-1 and HPBL in the early phase after exposure; however, the IR induced expression levels of PIG3 are greater in AHH-1 than HPBL.

[Anti-allergic effects of the probiotic preparations of enterococcus on experimental allergic rhinitis in mice].

OBJECTIVE: The aim of this study was to investigate the anti-allergic effects of lysozyme/heat-treated Enterococcus faecalis FK-23 (LFK) and heat-treated Enterococcus faecium sp. TN-3 (TN) on experimental allergic rhinitis (AR). METHODS: A total of twenty-four BALB/c mice were divided into four groups randomly: (1) positive control group, (2) LFK-fed group, (3) TN-fed group, and (4) negative control group. To establish the murine AR model, intraperitoneal injection and nasal drip with ovalbumin (OVA) were performed. Saline was used instead of OVA for negative control. Probiotic preparations of LFK and TN were orally administrated for 42 days [60 mg (0.5 ml)/d] in LFK-fed and TN-fed mice, respectively. The positive and negative control mice received saline orally for 42 days. Nasal rubbing and sneezing were monitored on d 21, d 27, and d 35. After the final challenge, mice were sacrificed on d 42, and eosinophilic infiltration into the nasal mucosa was quantified (H&E stain). IFN-gamma, IL4 and OVA-specific IgE levels in the sera and splenocyte culture supernatants were determined by ELISA kits. RESULTS: Nasal rubbing of LFK-fed mice was significantly reduced compared to the positive control group on day 27 (t = 2.95, P = 0.028). Both in the LFK-fed and TN-fed mice, nasal rubbing (t value was 3.75 and 3.06, P value was 0.005 and 0.011, respectively) and sneezing (t value was 2.56 and 3.35, P value was 0.038 and 0. 01, respectively) were significantly decreased compared to the positive control group on d 35. The H&E strain section of nasal tissue showed that eosinophil influx into the nasal mucosa decreased significantly both in the LFK-fed and TN-fed mice compared to the positive control group on day 42 (t value was 3.44 and 2.97, P value was 0.014 and 0.025, respectively); however, the LFK-fed mice and TN-fed mice had significant eosinophil influx into the nasal mucosa than that in the negative control group (t value was 2.54 and 3.39, P value was 0.044 and 0.015, respectively). There were no significant differences in the serum levels of IL-4 and OVA-specific IgE, as well as the levels of IFN-gamma and IL-4 in splenocyte culture supernatants between the LFK-fed group and positive control group on d 42 (all P > 0.05). Interestingly, the TN-fed mice had significantly higher serum levels of IFN-gamma compared to the LFK-fed mice [TN-fed mice: (27.07 +/- 3.83) pg/ml, LFK-fed mice: (14.83 +/- 0.99) pg/ml; Z = 2.49, P = 0.016], but not the negative control group [negative control group: (37.12 +/- 1.65) pg/ml; Z = 1.18, P = 0.343] on day 42. The serum levels of IL-4 were significantly lower in the TN-fed mice than those in the positive control group [TN-fed mice: (34.48 +/- 7.53) pg/ml, positive control group: (58.68 +/- 6.59) pg/ml; Z = 2.11, P = 0.035]; however, the levels were significantly higher in the TN-fed mice than those in the negative control group [negative control group: (20.22 +/- 1.75) pg/ml; Z = 2. 31, P = 0.021]. The TN-fed mice had significantly higher levels of IFN-gamma in splenocyte culture supernatants compared to the LFK-fed mice (Z = 2.72, P = 0.03) and the positive control group (Z = 2.30, P = 0.029), whilst the splenocyte culture supernatant levels of IL-4 (Z = 2.12, P = 0.034) and the serum levels of OVA-specific IgE (Z = 2.31, P = 0.021) were significantly lower in the TN-fed mice compared to the positive control mice. CONCLUSIONS: It is suggested that oral administration of probiotic LFK or TN may alleviate nasal symptoms and reduce nasal eosinophilia in the murine AR model. TN supplementation has obviously regulatory effects on the cytokine levels of IFN-gamma and IL-4, and significantly inhibitory effects on antigen-specific IgE levels.